what is the answer of the sum of a and b's age is 32; b and c's is 39; a and c's is 62. how old is c?

a+b+0C=32

0a+b+c=39
a+0b+c=62

subtract the second equation from the third.

a-b=23

add this and the first equation.
2a=55
a=55/2

but a+c=62 ; c=62-55/2=34.5
and finally, b=32-55/2=4.5

It is not good practice to construct problems in which the age answers are fractions.